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#873132 (Received by flhurricane at: 10:56 PM 27.Aug.2016) TCDAT2 HURRICANE GASTON DISCUSSION NUMBER 22 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072016 1100 PM AST SAT AUG 27 2016 Gaston has become a hurricane again with a well-defined eye on microwave images that has been occasionally showing up on conventional satellite pictures. Dvorak estimates are T4.5/77 kt from both TAFB and SAB, so the initial wind speed is increased to 75 kt. The environment near Gaston, other than some dry mid-level air, looks conducive for strengthening for the next day or so. While the environment doesn't change much in the next couple of days overall, Gaston is expected to move very slowly, which could upwell some cooler water. Thus the wind speed forecast will be leveled off after 24 hours. A more consistent weakening trend is expected beyond 72 hours when the cyclone moves over colder waters and experiences stronger shear. The latest NHC prediction is higher than the previous one, mostly owing to the initial conditions, and is close to a blend of the FSU Superensemble and the intensity consensus. Satellite fixes show that Gaston is moving slower to the northwest, at about 7 kt. The storm should continue to decelerate over the next day or so as it reaches a break in the subtropical ridge, and have a slow motion to the north or northeast from 24 to 48 hours. The next shortwave trough in the mid-latitude is forecast to reach Gaston in about 3 days, which will likely cause the hurricane to recurve to the east-northeast, albeit at a slower rate of speed than you normally see over the North Atlantic. Guidance has not changed much since the last cycle, and the official forecast is basically an update of the previous one, a bit slower than the model consensus. FORECAST POSITIONS AND MAX WINDS INIT 28/0300Z 29.6N 54.2W 75 KT 85 MPH 12H 28/1200Z 30.1N 54.7W 85 KT 100 MPH 24H 29/0000Z 30.7N 55.1W 95 KT 110 MPH 36H 29/1200Z 31.0N 55.2W 95 KT 110 MPH 48H 30/0000Z 31.4N 54.8W 90 KT 105 MPH 72H 31/0000Z 32.6N 52.2W 90 KT 105 MPH 96H 01/0000Z 34.6N 48.1W 85 KT 100 MPH 120H 02/0000Z 37.5N 42.0W 70 KT 80 MPH $$ Forecaster Blake |